diff --git a/src/dotty/tools/dotc/transform/Memoize.scala b/src/dotty/tools/dotc/transform/Memoize.scala
index f4b00d6a5e86..17a84484a115 100644
--- a/src/dotty/tools/dotc/transform/Memoize.scala
+++ b/src/dotty/tools/dotc/transform/Memoize.scala
@@ -43,6 +43,12 @@ import Decorators._
    */
   override def runsAfter: Set[Class[_ <: Phase]] = Set(classOf[Mixin])
 
+  override def checkPostCondition(tree: Tree)(implicit ctx: Context): Unit = tree match {
+    case tree: DefDef if !tree.symbol.is(Lazy | Deferred) =>
+      assert(!tree.rhs.isEmpty, i"unimplemented: $tree")
+    case _ =>
+  }
+
   override def prepareForDefDef(tree: DefDef)(implicit ctx: Context) = {
     val sym = tree.symbol
     if (sym.isGetter && !sym.is(NoFieldNeeded)) {
@@ -74,7 +80,7 @@ import Decorators._
         Thicket(fieldDef, getterDef)
       }
       else if (sym.isSetter) {
-        val Literal(Constant(())) = tree.rhs
+        if (!sym.is(ParamAccessor)) { val Literal(Constant(())) = tree.rhs }
         val initializer = Assign(ref(field), ref(tree.vparamss.head.head.symbol))
         cpy.DefDef(tree)(rhs = transformFollowingDeep(initializer))
       }
@@ -82,5 +88,5 @@ import Decorators._
                 // neither getters nor setters
     else tree
   }
-  private val NoFieldNeeded  = Lazy | Deferred | ParamAccessor | JavaDefined
+  private val NoFieldNeeded  = Lazy | Deferred | JavaDefined
 }
\ No newline at end of file
diff --git a/src/dotty/tools/dotc/transform/ResolveSuper.scala b/src/dotty/tools/dotc/transform/ResolveSuper.scala
index 23ff45a7c0b1..6b1b55b0a73f 100644
--- a/src/dotty/tools/dotc/transform/ResolveSuper.scala
+++ b/src/dotty/tools/dotc/transform/ResolveSuper.scala
@@ -50,32 +50,32 @@ class ResolveSuper extends MiniPhaseTransform with IdentityDenotTransformer { th
 
   override def treeTransformPhase = thisTransform.next
 
+  /** Returns the symbol that is accessed by a super-accessor in a mixin composition.
+   *
+   *  @param base       The class in which everything is mixed together
+   *  @param member     The symbol statically referred to by the superaccessor in the trait
+   */
+  private def rebindSuper(base: Symbol, acc: Symbol)(implicit ctx: Context): Symbol = {
+    var bcs = base.info.baseClasses.dropWhile(acc.owner != _).tail
+    var sym: Symbol = NoSymbol
+    val SuperAccessorName(memberName) = acc.name: Name // dotty deviation: ": Name" needed otherwise pattern type is neither a subtype nor a supertype of selector type
+    ctx.debuglog(i"starting rebindsuper from $base of ${acc.showLocated}: ${acc.info} in $bcs, name = $memberName")
+    while (bcs.nonEmpty && sym == NoSymbol) {
+      val other = bcs.head.info.nonPrivateDecl(memberName)
+      if (ctx.settings.debug.value)
+        ctx.log(i"rebindsuper ${bcs.head} $other deferred = ${other.symbol.is(Deferred)}")
+      sym = other.matchingDenotation(base.thisType, base.thisType.memberInfo(acc)).symbol
+      bcs = bcs.tail
+    }
+    assert(sym.exists)
+    sym
+  }
+
   override def transformTemplate(impl: Template)(implicit ctx: Context, info: TransformerInfo) = {
     val cls = impl.symbol.owner.asClass
     val ops = new MixinOps(cls, thisTransform)
     import ops._
 
-    /** Returns the symbol that is accessed by a super-accessor in a mixin composition.
-     *
-     *  @param base       The class in which everything is mixed together
-     *  @param member     The symbol statically referred to by the superaccessor in the trait
-     */
-    def rebindSuper(base: Symbol, acc: Symbol): Symbol = {
-      var bcs = cls.info.baseClasses.dropWhile(acc.owner != _).tail
-      var sym: Symbol = NoSymbol
-      val SuperAccessorName(memberName) = acc.name: Name // dotty deviation: ": Name" needed otherwise pattern type is neither a subtype nor a supertype of selector type
-      ctx.debuglog(i"starting rebindsuper from $cls of ${acc.showLocated}: ${acc.info} in $bcs, name = $memberName")
-      while (bcs.nonEmpty && sym == NoSymbol) {
-        val other = bcs.head.info.nonPrivateDecl(memberName)
-        if (ctx.settings.debug.value)
-          ctx.log(i"rebindsuper ${bcs.head} $other deferred = ${other.symbol.is(Deferred)}")
-        sym = other.matchingDenotation(cls.thisType, cls.thisType.memberInfo(acc)).symbol
-        bcs = bcs.tail
-      }
-      assert(sym.exists)
-      sym
-    }
-
     def superAccessors(mixin: ClassSymbol): List[Tree] =
       for (superAcc <- mixin.decls.filter(_ is SuperAccessor).toList)
         yield polyDefDef(implementation(superAcc.asTerm), forwarder(rebindSuper(cls, superAcc)))
@@ -94,5 +94,18 @@ class ResolveSuper extends MiniPhaseTransform with IdentityDenotTransformer { th
 
     cpy.Template(impl)(body = overrides ::: impl.body)
   }
+
+  override def transformDefDef(ddef: DefDef)(implicit ctx: Context, info: TransformerInfo) = {
+    val meth = ddef.symbol.asTerm
+    if (meth.is(SuperAccessor, butNot = Deferred)) {
+      assert(ddef.rhs.isEmpty)
+      val cls = meth.owner.asClass
+      val ops = new MixinOps(cls, thisTransform)
+      import ops._
+      polyDefDef(meth, forwarder(rebindSuper(cls, meth)))
+    }
+    else ddef
+  }
+
   private val PrivateOrDeferred = Private | Deferred
 }
diff --git a/src/dotty/tools/dotc/transform/SuperAccessors.scala b/src/dotty/tools/dotc/transform/SuperAccessors.scala
index 8a531de8d835..f727201b2895 100644
--- a/src/dotty/tools/dotc/transform/SuperAccessors.scala
+++ b/src/dotty/tools/dotc/transform/SuperAccessors.scala
@@ -89,8 +89,9 @@ class SuperAccessors extends MacroTransform with IdentityDenotTransformer { this
 
       val superAcc = clazz.info.decl(supername).suchThat(_.signature == sym.signature).symbol orElse {
         ctx.debuglog(s"add super acc ${sym.showLocated} to $clazz")
+        val maybeDeferred = if (clazz is Trait) Deferred else EmptyFlags
         val acc = ctx.newSymbol(
-            clazz, supername, SuperAccessor | Private | Artifact | Method,
+            clazz, supername, SuperAccessor | Private | Artifact | Method | maybeDeferred,
             ensureMethodic(sel.tpe.widenSingleton), coord = sym.coord).enteredAfter(thisTransformer)
         // Diagnostic for SI-7091
         if (!accDefs.contains(clazz))